CN107850282B

CN107850282B - Lighting mechanism and motor vehicle headlight

Info

Publication number: CN107850282B
Application number: CN201680042909.0A
Authority: CN
Inventors: L.陶德特; J.普兰克
Original assignee: ZKW Group GmbH
Current assignee: ZKW Group GmbH
Priority date: 2015-07-28
Filing date: 2016-07-18
Publication date: 2020-06-23
Anticipated expiration: 2036-07-18
Also published as: CN107850282A; WO2017015684A1; AT517523B1; AT517523A1; EP3329179A1; EP3329179B1; US20180128443A1; JP6481054B2; US10018317B2; JP2018520483A; AT517523A9

Abstract

The invention relates to a lighting device (1) for a headlight, in particular a motor vehicle headlight, comprising a plurality of light sources (100), a light guide device (10) having a plurality of light guide elements (11, 12, 13), and a downstream imaging optics element (200), wherein each light-guiding element (11, 12, 13) has a light entry face and a light exit face, wherein the light-guiding elements (11, 12, 13) are arranged in at least one row, wherein the light-guiding elements of at least one row are configured as high-beam light-guiding elements (11) and form a high-beam row, wherein each high beam-light guide element (11) comprises a lower light guide surface (24), wherein the lower light-guiding surface (24) has a structure (25) at least in regions, in which the light beam (52) is reflected. The invention also relates to a motor vehicle headlight having such a luminous element.

Description

Lighting mechanism and motor vehicle headlight

Technical Field

The invention relates to a lighting device for a headlight, in particular a motor vehicle headlight, comprising a plurality of light sources, a light guide with a plurality of light guide elements, and a downstream imaging optics element, wherein each light guide element has a light entry surface and a light exit surface, wherein the light guide elements are arranged in at least one row.

Background

Such light-emitting units, which are also referred to as pixel light modules, are common in vehicle construction and are used, for example, for imaging glare-resistant high beams, in that the light is usually emitted by a plurality of artificial light sources and is bundled in the emission direction by a corresponding plurality of light guides (additional optical means (Vorsatzoptik)/primary optical means) arranged next to one another. The light guide has a relatively small cross section and therefore emits the light of the individual light sources assigned to the light guide very intensively in the emission direction. The pixel light headlight is very flexible with respect to the light distribution, since the illumination intensity can be individually adjusted for each pixel, i.e. for each light guide, and an arbitrary light distribution can be achieved.

On the one hand, a concentrated emission of the light guide is desirable in order to satisfy, for example, legal requirements with respect to the dark line of the motor vehicle headlight or to achieve (umzusetzen) adaptive, flexible fade-out scenes (ausblendszeneries), and on the other hand, in this way, disturbing inhomogeneities occur in the region of the light pattern in which a homogeneous, concentrated and directed illumination is desired, as is the case, for example, in the high beam distribution.

This problem can be improved by reducing the height of the high beam distribution, which is, however, contrary to customer requirements. There is therefore a need for improved measures for homogenizing the high beam distribution.

Different measures or methods are known from the prior art, which are based on defocusing on the one hand and on light scattering, which is achieved, for example, by means of structures that scatter light, on the other hand.

US 8,011,803B2 relates to a fog headlight which comprises an additional collimating optical means with an attached (angelängter) wave-like deflection surface which is inclined with respect to the main emission direction of the LED, whereby on the one hand the light is deflected but also scattered, so that the homogeneity is improved.

DE 2009053581B 3 relates to the primary optical mechanism of a matrix/pixel module. The exit surface of the optical element on the end side is provided with a corrugated spacer structure (Polsterstruktur).

DE 102008005488 a1 discloses a fine structured surface for an optical mechanical unit with a plurality of structural elements by means of which the light spot is spread out in the horizontal direction. In the case of the superposition of the light spots, the edges (Kanten) become blurred, as a result of which a more uniform overall light distribution occurs.

DE 102010027322 a1 describes refractive micro-optical component at the light exit surface of the primary optical component.

EP 2587125 a2 discloses microstructures on the light exit side of the primary optics of a pixel headlight.

US 5,727,108 discloses prismatic boundary surfaces for the add-on optical mechanism of Compound Parabolic Concentrators (CPCs).

Disclosure of Invention

The object of the present invention is to provide a luminous element for a headlight which on the one hand achieves a comparatively homogeneous high beam distribution and on the other hand achieves a concentrated and directed illumination of the high beam region.

The object is achieved by a luminous element for a headlight of the type mentioned at the outset, which is characterized according to the invention in that the light guide elements of at least one row are designed as high beam light guide elements and form a high beam row, wherein each high beam light guide element comprises a lower light guide surface, wherein the lower light guide surface has a structure at least in places at least in the region in which the light beam is reflected.

The invention represents a technically simple and cost-effective measure for locally influencing the light distribution in the respective high-beam light guide element and thus for achieving a more uniform high-beam light distribution.

The light-guiding element is typically embodied as a solid body (Vollk ö rper) and preferably consists of a single continuous optical medium, wherein the light-guiding takes place within the medium.

Advantageously, the structure is formed in a region of the lower light-guiding surface which is adjacent to the light exit surface and in which the light is reflected. The arrangement of the structure only in the vicinity of the light exit area of the respective high-beam light guide element of the high-beam row can thus improve the superposition of the primarily reflected light beams with the directly radiated light.

The light emitted by the light source and the light injected into the light-guiding element are expediently totally reflected by the lower light-guiding surface.

Advantageously, the structure formed on the lower light-guiding surface comprises structural elements having a periodic geometry.

It has proven to be particularly advantageous if the structure is designed in the form of a groove, the groove being oriented transversely to the optical axis of the light-emitting means.

The grooves can have a width of about 0.2-0.4 mm and a height of 0.015-0.03 mm.

In a variant, it is provided that, starting from the light exit surface, 6 to 15 grooves are formed in the lower light guide surface.

As a rule of thumb, the design of a lighting mechanism for a pixel light headlight is particularly effective when the light guiding elements are arranged in exactly three rows arranged one above the other (which together form a high beam distribution). In this arrangement, the upper row can be configured as a top field row, the middle row as an asymmetrical row and the lower row as a high beam row, wherein the high beam row formed by the high beam/light guide elements is provided with the structure disclosed as described herein. Suitably, the lowermost row is the high beam row.

In other embodiments, all light guiding elements can be designed as high-beam light guiding elements, which are arranged in exactly one row. Such a light emitting mechanism is also called a pixel high beam module.

In a further development of the invention, the light exit surfaces of the individual light guide elements can be part of a common light exit surface, wherein the individual light exit surfaces adjoin one another, the common light exit surface typically being a curved (gekr ü mmte) surface, which generally follows (folgt) the Petzval surface of the imaging optics (e.g. imaging lens).

A further subject matter of the invention relates to a headlight, in particular a motor vehicle headlight, comprising a lighting device according to the invention as disclosed herein. Such headlamps are also referred to as pixel light headlamps.

Drawings

The invention and its advantages are described in more detail in the following, non-limiting examples, which are illustrated in the attached drawings. The attached drawings are as follows:

a perspective illustration of the basic construction of a lighting mechanism according to the invention is shown in figure 1,

a diagram of the total light distribution obtained by the lighting mechanism from figure 1 is shown in figure 2,

a detailed view in the direction of light propagation towards the additional optical mechanism from figure 1 is shown in figure 3,

in figure 4 a side view of a high beam-light guiding element according to the prior art is shown,

the light intensity distribution (light intensity simulation) derived from the high beam-light guiding element of figure 4 is shown in figure 5,

the intensity profile of the light intensity distribution from figure 5 is shown in figure 6,

in figure 7 a side view of a high beam-light guiding element according to the invention is shown,

a graphical representation of the light intensity distribution originating from the high beam-light guiding element of figure 7 is shown in figure 8,

the intensity profile resulting from the light intensity distribution of figure 8 is shown in figure 9,

in FIG. 10, a vertical section through a high beam-light guide element according to the invention is shown (Vertikalschnitt), an

Details derived from fig. 10 are shown in fig. 11.

Detailed Description

Fig. 1 shows a perspective illustration of the basic structure of a lighting device 1 according to the invention. The lighting means 1 comprises a plurality of LED light sources 100 (see fig. 7 for this purpose, however) which are not shown in greater detail in fig. 1, and an additional optical means 10 (= primary optical means) which is positioned in the light emission direction, and a downstream imaging optical means 200 (in the form of a single lens 200). The additional optical means 10 comprise light-guiding

elements

11, 12, 13 which are arranged in three rows and which extend radially with respect to a common end plate 26. The end plate 26 is bounded on the radiation side by light exit surfaces 23', wherein the light exit surfaces 23 (see fig. 7) of the individual light guiding elements are in each case part of the common light exit surface 23', wherein the individual light exit surfaces 23 adjoin one another. The common light exit surface 23' is typically a curved surface, which generally follows the Petzval surface of the imaging lens 200. For certain applications, intentional deviations in the curvature of the common light exit surface 23' can also be used in order to use the imaging distortions for light homogenization in the edge region. Each light-guiding

element

11, 12, 13 is assigned an LED light source 100 (see fig. 7) according to a per se known type. The illumination intensity can be individually adjusted for each

light guiding element

11, 12, 13, whereby an arbitrary light distribution can be achieved. In the additional optical unit 10 shown in fig. 1, the upper row is configured as a top field row of a plurality of top field light guide elements 13. The middle row is configured as an asymmetrical row of a plurality of asymmetrical light-guiding elements 12, and the lower row is configured as a high-beam row of a plurality of high-beam light-guiding elements 11. These three rows together in the activated state constitute a high beam profile. The high-beam light guide element 11 is provided with a groove structure 25 on its lower light guide surface 24 (see fig. 7 for this purpose), wherein the groove 25 is oriented transversely to the optical axis 16 of the lighting means 1. Fig. 3 shows a detail view in the direction of light propagation towards the additional optical mechanism 10 from fig. 1.

The light-guiding

elements

11, 12, 13 can be made, for example, of silicone, plastic, glass or any other material suitable for light-guiding. The light-guiding

elements

11, 12, 13 are embodied as solid bodies and consist of a single continuous optical medium, wherein the light-guiding takes place within the medium. The light-guiding

elements

11, 12, 13 have a substantially square or rectangular cross section and diverge in the light emission direction, where they ultimately extend, as described above, on the emission side relative to the common end plate 26, which is limited on the emission side by the light exit plane 23' (see fig. 3).

Fig. 2 shows a representation of the total light distribution (= pixel light distribution) which can be detected by the lighting means 1 from fig. 1 when viewed through the imaging lens on a measurement screen, wherein fields arranged in a matrix of horizontal and vertical axes U and V can be seen in three rows, wherein the upper row, which comprises a plurality of high-beam light strips, is used for the illumination of the high-beam region, the middle row is used for the illumination in the asymmetrical region (formation of the light/dark boundary) and the lower row is used for the illumination of the front field of the pixel light headlight.

Fig. 4 shows a side view of a high-beam light-guide element 11 'according to the prior art, the high-beam light-guide element 11' being a solid body with a light entry face 21 via which the light emitted by the LED light sources is entered into the light-guide element 11', the light being guided along the high-beam light-guide element 11' onwards to a light exit face 23, furthermore, fig. 4 shows an exemplary light path (Strahlengänge) proceeding from the light entry face 21, in which a beam 50 emerges as direct light exit and a beam 51 reflected at the lower light-guide face 24 emerges as indirect light exit fig. 4 also shows the upper light-guide face 22, whereas the light-guide face laterally bounding the solid body is not provided with drawing marks for presentability reasons.

Fig. 5 exemplarily shows a light intensity distribution 30 (ray tracing simulation of a light technique by a light intensity sensor, in which a gray-scale image corresponding to a luminous intensity is obtained) derived from the high beam-light guiding element 11' of fig. 4. An intensity maximum 31 can be determined in the area below the distal section; in contrast, in the region above the distal section there is first an intensity drop 32, which causes a clearly visible inhomogeneity by an inverse increase 33 of the intensity (Gegenanstieg). Fig. 6 shows the intensity profile of the light intensity distribution from fig. 5, in which the reverse lift-off 33 can be seen well. The reason for this inhomogeneity is, in particular, the incomplete overlap and the transition between the directly radiated light 50 and the light 51 reflected at the lower light-guiding surface 24.

Fig. 7 shows a side view of a high beam-light guiding element 11 according to the invention. The high-beam light guide element 11 according to the invention differs from the high-beam light guide elements from the prior art (high-beam light guide element 11', see fig. 4) in that a groove-shaped structure 25 is formed on the lower light guide surface 24 in the region in which the beam 52 is reflected. The remaining configuration of the high beam-light guiding element 11 corresponds to the configuration from fig. 4 and reference is made to the description thereof further above. Fig. 7 furthermore shows an exemplary light path from the light entry surface 21, wherein the radiation beam 50 emerges as direct light exit and the radiation beam 52 reflected at the groove structure 25 of the light guide surface 24 emerges as indirect light exit. The groove structure 25 scatters and shapes the light 52 just in the region in the transition between the directly radiated light 50 and the light 52 reflected at the groove structure 25 of the underlying light guiding surface 24. The light distribution and thus the light homogeneity can be influenced by the trench structure 25.

Fig. 8 exemplarily shows a light intensity distribution 30' of the high beam-light guiding element 11 according to the present invention derived from fig. 7 (ray tracing simulation of light technique by means of a light intensity sensor, in which a gray scale image corresponding to the luminous intensity is obtained). Said intensity maximum 31 can be determined in the area below said distal section; a continuous decrease in the intensity can generally be seen in the area above the distal section, and the light image is significantly more uniform than in the prior art. Fig. 9 shows the intensity profile of the light intensity distribution from fig. 8, from which the continuous intensity drop and the improved homogeneity (indicated by reference numeral 34 in fig. 7) can be clearly seen in the transition between the directly radiated light 50 and the light 52 reflected at the trench structure 25. The upward tapping (Auslauf) (see fig. 2) can be better designed or optimized by means of the trench structure.

Fig. 10 shows a vertical section through a high beam-light guiding element 11 according to the invention. As can be seen therein, the groove 25 runs transversely to the optical axis (or light propagation direction) and is formed along the (imaginary) base line TK on the lower light-guiding surface 24. In the example shown, a total of 9 grooves are formed starting from the light exit area 23. The groove 25 has, for example, a width of 0.3mm and a height of 0.015-0.03 mm.

Fig. 11 shows a detail from fig. 10 (indicated in fig. 10 by a dashed circle) an optimized embodiment can be obtained in that the base line TK is the boundary of the light-guiding element in this case, points P (Pi, Pi +1, Pi + 2) are depicted on such a curved (imaginary) curve TK, which points have a constant distance S from one another, the distance (or wavelength) for a specific far-light-guiding element being, for example, S =0.30mm, adjacent points Pi and Pi +1, a line segment (Strecke) in the bisecting point Hi of which a normal is established, three points Pi, Si, Pi +1 of a spline curve (aust ü tzstellen) above which a vertex Si. is established in the amplitude of the distance = Hi, the magnitude of the amplitude repeatedly varying, the magnitude of the amplitude being varied by means of a corresponding geometry, the simulation of the light technique being carried out by means of a type and in a manner known per se, the obtained light image (or amplitude variation) results in that the best of this gradient of the light-guiding grooves (aust) has to be determined by the vertical light-guiding surface (agche) of which the light source has the magnitude of the gradient) determined by the normal curve of the vertical light-guiding surface (stczke) and the vertical light-guiding surface (stsfk) having the magnitude of the angle of the perpendicular angle of the light-guiding element (stsfk) determined by means of the perpendicular to be determined by means of the normal of the light-guiding element (stsfk) of the.

The examples shown are only some examples of many and should not be construed as limiting.

Claims

1. Light-emitting means (1) for a motor vehicle headlight, comprising a plurality of light sources (100), a light guide means (10) having a plurality of light guide elements (11, 12, 13) and a downstream imaging optical means element (200), wherein each light guide element (11, 12, 13) has a light entry face and has a light exit face, wherein the light guide elements (11, 12, 13) are arranged in at least one row, and the light guide elements of at least one row are designed as high-beam light guide elements and form a high-beam row, wherein each high-beam light guide element comprises a lower light guide face (24), characterized in that the lower light guide face (24) has a structure (25) at least in regions in which a light beam (52) is reflected, wherein the structure (25) is designed in regions of the lower light guide face (24), the region is adjacent to the light exit surface (23) and in which the light is reflected, and the structure (25) is designed in the form of a groove, wherein the groove is oriented transversely to the optical axis (16) of the light-emitting means and has a width of 0.2-0.4 mm and a height of 0.015-0.03 mm.

2. The illumination mechanism according to claim 1, characterized in that the lower light-guiding surface (24) totally reflects the incident light beam.

3. The light mechanism of claim 1 or 2, wherein the grooves have a periodic geometry.

4. A light-emitting mechanism according to claim 1 or 2, characterized in that 6-15 grooves are formed on the lower light-guiding surface (24) from the light exit surface.

5. A light-emitting mechanism according to claim 1 or 2, characterized in that the light-guiding elements (11, 12, 13) are arranged in exactly three rows arranged one above the other, which together form a high-beam distribution.

6. The light mechanism of claim 5, wherein the lowermost row is the high beam row.

7. A light-emitting mechanism according to claim 1 or 2, characterized in that all light-guiding elements are configured as high-beam light-guiding elements, which are arranged in exactly one row.

8. A light-emitting mechanism according to claim 1 or 2, characterized in that the light exit faces (23) of the light guiding elements (11, 12, 13) are part of a common light exit face (23'), wherein the respective light exit faces (23) are adjacent to each other.

9. Motor vehicle headlight comprising a lighting mechanism (1) according to any one of the claims 1 to 8.